The WOUND-Q Function and Symptoms Scales for Chronic Lower Extremity Wounds: A Validation Study.

Abstract

Objective: Determine the validity and reliability of the LIMB-Q scales, Function, and Symptoms in patients with chronic lower extremity wounds. Approach: Cognitive debriefing interviews with people with current or previous wounds were conducted to examine content validity. Scales were field-tested in an international sample of people with chronic lower extremity wounds sourced from an online platform (i.e., Prolific). Psychometric properties were examined using the Rasch Measurement Theory analysis. A test-retest reproducibility study was performed, and construct validity was examined. Results: Content validity was established after 10 cognitive interviews. A total of 233 people with lower extremity wounds (age 19-80 years, mean 39.3) participated in the field test. All 25 items tested demonstrated good fit to the Rasch model with ordered thresholds. One item had a fit residual outside ±2.5, but no items had significant χ2 values after Bonferroni adjustment. Reliability was high with the person separation index, Cronbach alpha, and intraclass correlation coefficient values >0.8. Strong correlations were found between the Function and Symptoms scales and EQ-5D dimensions measuring similar constructs as well as the EQ-5D global score. All hypotheses for construct validity were confirmed. Innovation: Patient-reported outcome measures are an important component of patient-centered care, as they capture the patient's perspective in a rigorous and reproducible way. Adding these two scales to the WOUND-Q provides a means to measure function and symptoms associated with lower extremity wounds. Conclusion: These new WOUND-Q scales can be used to measure outcomes important to patients with lower extremity wounds in clinical settings and research studies.